1. Technical Field
The present invention relates to a vertical probe card and a method for manufacturing the same.
2. Related Art
After integrated circuits on a wafer are completed, testing is conducted in order to identify bad dies before a packaging process is carried out so that bad dies will not be packaged and unnecessary cost will not increase.
Normally, a wafer under testing is placed in an environment of 80 to 150 degrees Celsius. In such a high temperature, the transverse thermal expansion of, for example, a 12-inch wafer, which has a coefficient of thermal expansion (CTE) of 2.8 ppm/K, is 23 to 44 micrometers. A probe card made of FR-4 material with a CTE of 18 ppm/K will transversely expand in a range of from 150 to 283 micrometers. Those thermal expansions will exert adverse influence to the alignment accuracy between the probes of the probe card and aluminum pads on the wafer under testing.
In addition, probes of a present probe card are formed with hard material, which may easily damage pads on a wafer under testing or metal layers beneath bumps.